Tool changers for forging presses



Feb. 15, 1966 K, KNO LES 3,234,648

TOOL GHANGERS FOR FORGING PRESSES Filed May 23, 1963 lNvEN-roIz ke z 'lwKnow/es United States Patent Ofifice 3,234,648 Patented Feb.'15, 19663,234,648 TOOL CHANGERS FOR FORGING PRESSES Keith Knowles, Shetiieid,England, assignor to The British Iron and Steel Research AssociationFiled May 23, 1963, Ser. No. 282,755 6 Claims. (Cl. 29568) Thisinvention relates to tool changers for forging presses.

In the use of conventional single-acting vertical pushdown type forgingpresses it is necessary after different forging operations to extractthe forge tools and to insert new tools for subsequent operations. Thistool changing is time-consuming and gives rise to delay betweensuccessive operations with different tools which is more than normallyundesirable since this delay at the same time may give rise to orincrease a requirement to reheat ingots during forging.

One object of this invention is to provide for automatically changingthe tools in a forging press within a short time compared with thatnormally required.

In one aspect the present invention provides apparatus for changingtools in a forging press, comprising a tool carrying assembly for twosets of press tools, which assembly is arranged for controlleddisplacement whereby .a selected tool from either set may be located ina predetermined position, for the set in question, relative to a forgingpress, and means for transferring a selected tool from the associatedpredetermined position towards the press.

In order that the present invention may be clearly understood, the samewill now be more fully described, by way of example, with reference tothe drawings accompanying the provisional specification, in which:

FIGURE 1 is a side elevation of one embodiment with the sides ofhydraulic cylinders 12 and 13 broken away to show the pistons, and thecatch on the press which engages the catch means on the tool changershown in phantom lines; and

FIGURE 2 is a sectional end elevation of FIGURE 1 taken at A-A.

The illustrated apparatus is mounted in a framework 1 which is itselfcarried on, or formed integrally with, a chassis 2. The chassis 2 isprovided with wheels 3 which allow the apparatus to be transported alonga track 4 to a position at one end of the track in close proximity to aforging press (not shown) for initial tool loading and subsequent toolchanging, and also away from the press for ease of maintenance or otheroperations on the apparatus itself, or on the press.

A double tool set carrying assembly is journalle d in bearings 5 fixablysupported in the framework 1, and generally comprises two coaxialcylindrical units which will be referred to as the inner and outer toolunits. The inner tool unit comprises two annular plates 6 carryingbetween them slotted guide members 7. These guide members are arrangedsymmetrically around the plates 6 with the slots of each pair in facingdisposition, whereby press tools 8 having suitable flanges may beslidably located between the pairs of guide members in cartridge manneras more clearly indicated in FIGURE 2. The annular plates 6 are providedwith openings 9 corresponding to the tool section for insertion andextraction of the tools.

The outer tool unit is of similar form to the inner tool unit andcorresponding elements are denoted by the same reference numerals withthe addition of an a.

The tools selected for insertion into the press are positioned about thevertical plane through the common cylindrical axis of the assembly asillustrated by the two uppermost tools 8 and 8a in FIGURE 2 and theseparticular tool positions are arranged to be in line with apredetermined tool receiving positions in the press. The press will beprovided with guides to receive tools when the guides are appropriatelypositioned.

The inner and outer tool units are adapted for independent rotation by acommon reversible motor 10 driving two wheels 11 carrying spring-biasedpawls which cooperate with inwardly projecting teeth on the hub members11a to form two oppositely acting ratchets so that drive in onedirection rotates one tool unit with the other fixed, and drive in theother direction rotates the other unit with the first fixed. Individualpositioning devices are associated with each tool position in the unitswhereby a selected tool, or tools one from each unit, are positioned forinsertion into the press. These positioning devices co-operate with adetent which is actuated by a hydraulic cylinder 12 and which isintroduced to lock the units when the selected tool or tools aresuitably positioned.

The selected tools when positioned for insertion are, as describedabove, on a common axis with the respective tool receiving positions ofthe press, and also with actuators shown as hydraulic or pneumaticcylinders 13 employed to propel these tools into the tool guides of thepress. It may be necessary to bridge any gap which would otherwise occurbetween the tool units and the press, and a suitable bridge assembly 14is shown for this purpose. Also a location stop and catch assembly isprovided for correct positioning of the tool units and bridge memberrelative to the press.

This catch assembly may comprise a pivotally mounted arm 15 pierced atone end by a vertical hole 15a and pivotally attached at its other endto the ram of a hydraulic cylinder 15b. When the tool changer approachesthe press, the hydraulic cylinder 15b swings the end of the arm 15pierced by the hole 15a upward, but subsequently permits it to drop whenthe pin 15c on the press catch 15d is beneath the hole.

To ensure locking of a tool in the press, the press tool guides areprovided, at their ends nearer the apparatus, with detent mechanismswhich are pushed to an inoperative position when a tool is inserted.However, the tool is pushed beyond the detent location and onwithdrawing the rams of cylinders 13 the detents adopt operativepositions to lock the tools in the press.

The above particular description has dealt only with insertion of toolsand this will be the case for initial tool loading of the press, forexample. For subsequent tool changes, one or both of the loaded toolsare first extracted, and it will be seen that the tool units are alreadyin the correct positions to receive the tools from the press. The ramsof cylinders 13 are provided with suitable means for engaging the toolsin the press to withdraw same, and they will, at the same time, push thepress tool locking detents to their inoperative positions.

The cylinder rams may be provided at their ends with suitable,conventional quick-connecting coupling arrangements 13a comprising ataper lead-in and ball lock device, for example. Such a device would beemployed for extraction of tools, the latter being provided withcomplementary devices. Means would then be required to re lease suchlocking devices when appropriate, and may comprise solenoids on thecylinder rams, for example. Suitable couplings may be purchased from theHansen Manufacturing Company, of 4033 W. th Street, Cleveland, Ohio. Theexact model selected will depend upon the nature of the complementarydevice carried by the tools to be changed.

It may be found desirable to taper the tool guide flanges at both endsto facilitate insertion and withdrawal of tools relative to the guides.

Although the invention has been described by way of example withreference to a particular embodiment it is not intended that it belimited thereto. Clearly various modifications can be \made in the aboveembodiment without departing from the scope of the invention; forexample, individual driving means may be employed for independentrotation of the inner and outer tool units, either simultaneously, orotherwise, by use of gears, chains, or directly. Also the tool insertionand withdrawal means shown as cylinders 13 may be comprised by ballscrew lead shafts. In other forms of the invention the tool bearingassembly may be in the form of a beam mounted on a frame fordisplacement along its axis by sliding, in a horizontal or verticaldisposition, for example. Two sets of tools may be carried, being upperand lower tools for the present application to forging presses, with apair of tools, one from each set, carried in slotted guide members inthe upper and lower portions of two-tool housings arranged along thebeam.

Common actuator means may be employed for insertion of the pair of toolsfrom any housing into the press, or withdrawal from the press into thebeam. Alternatively, individual actuator means may be associated witheach set of tools, that is to say, with the upper and lower portions ofthe tool housingsf Again, as in the above-described embodiment of FIG-URES 1 and 2, the apparatus may comprise independently controllable toolcarrying units, in this case the units being of parallel beam form. Inembodiments of the latter form independent drive means and actuatormeans will be associated with each tool unit.

Furthermore the invention is not necessarily applicable to forgingpresses employing two changeable tools and may comprise a unit, orunits, for one or more sets of tools as appropriate, although theinvention has been developed with a view to particular application toautomatic forging presses of the former kind.

I claim:

1. For association with a forging press having a pair of interchangeabletools, tool changing apparatus comprising a carriage movable towards andaway from an associated press, a pair of first and second cylindricaltool magazines mounted on said carriage for rotation about a common axisdisposed parallel to the plane of the carriage, first and secondpluralities of slotted openings for receiving tools, said openings beingrespectively and circumferentially distributed in said magazines withthe axes of said openings disposed parallel to said common axis, drivemeans to respectively independently rotate said magazines, locking meansto lock said magazines against rotation with any selected pair of saidopenings, one from each plurality thereof, disposed in predeterminedrotational angular positions, and tool transfer means aligned with saidpredetermined positions to eject tools from said selected openingstowards said press and to withdraw tools thereinto from said press.

2. Apparatus according to claim 1 comprising catch means mounted on saidcarriage towards one axial end of said magazine to latch said carriagewith said press during tool transfer therebetween.

3. Apparatus according to claim 2 comprising bridge means mounted onsaid carriage and including first and second slideways respectivelyaligned with said predetermined positions.

4. Apparatus according to claim 1 wherein said tool transfer meanscomprise a pair of hydraulic rams respectively aligned with saidpredetermined positions.

5. For association with a forging press having a pair of first andsecond tool carrying members arranged for pressing action by relativereciprocation along a predetermined axis and each adapted to receiveinterchangeable press tools: tool changing apparatus comprising a pairof first and second slideways disposed normally to said predeterminedaxis with one end of each slideway respectively adjacent predeterminedpositions of said tool carrying members, a first tool magazine includinga plurality of slotted openings for receiving tools, said openings beingdisposed with their axes parallel to said slideways and which firstmagazine is mounted to move its openings along a first path remote fromsaid press to traverse its openings successively into a first fixedposition aligned with said first slideway adjacent the other endthereof, a second tool magazine including a plurality of slottedopenings disposed with their axes parallel to said slideways and whichsecond magazine is mounted to move its openings along a second pathremote from said press to traverse its opening successively into asecond fixed position aligned with said second slideway adjacent theother end thereof, drive means to respectively independently move saidmagazines along their respective paths, locking means to lock saidmagazines against movement with any selected pair of said openings, onefrom each magazine, respectively disposed in said fixed positions, andreciprocable tool transfer means aligned with said fixed positionsadjacent the ends thereof remote from said press to eject tools fromsaid selected openings along said slideways towards said press and towithdraw tools from said press along said slideways into said selectedopenings.

6. For association with a forging press having a pair of tool carryingmembers-for receiving changeable tools, tool changing apparatuscomprising a first tool magazine carrying a plurality of tool holdersand mounted to move each tool holder along a first path into a firstposition aligned with a predetermined position of one tool carryingmember of an associated press, a second tool magazine likewise carryinga plurality of tool holders and mounted to move each tool holder carriedthereby along a second path into a second position aligned with a predetermined position of the other tool carrying member of said press,said first and second paths lying wholly outside the confines of saidpress, means for independently driving each of said first and secondmagazines to move said tool holders along their respective paths;looking means to lock said first and second magazines with any selectedtool holder thereof aligned in said first and second positions,respectively; and first and second tool transfer means respectivelyaligned with said first and second magazine positions to transferselected tools between said magazines and press.

References Cited by the Examiner UNITED STATES PATENTS 2,363,208 11/1944 Sulzer.

3,134,350 5/1964 Danly 299 FOREIGN PATENTS 1,101,910 3/1961 Germany.

CHARLES W. LANHAM, Primary Examiner.

WILLIAM J. STEPHENSON, Examiner.

G. P. CROSBY, Assistant Examiner,

1. FOR ASSOCIATION WITH A FORGING PRESS HAVING A PAIR OF INTERCHANGEABLETOOLS, TOOL CHANGING APPARATUS COMPRISING A CARRIAGE MOVABLE TOWARDS ANDAWAY FROM AN ASSOCIATED PRESS, A PAIR OF FIRST AND SECOND CYLINDRICALTOOL MAGAZINES MOUNTED ON SAID CARRIAGE FOR ROTATION ABOUT A COMMON AXISDISPOSED PARALLEL TO THE PLANE OF THE CARRIAGE, FIRST AND SECONDPLURALITIES OF SLOTTED OPENINGS FOR RECEIVING TOOLS, SAID OPENINGS BEINGRESPECTIVELY AND CIRCUMFERENTIALLY DISTRIBUTED IN SAID MAGAZINES WITHTHE AXES OF SAID OPENINGS DISPOSED PARALLEL TO SAID COMMON AXIS, DRIVEMEANS RESPECTIVELY INDEPENDENTLY ROTATE SAID MAGAZINES, LOCKING MEANS TOLOCK SAID MAGAZINES AGAIST ROTATION WITH ANY SELECTED PAIR OF SAIDOPENINGS, ONE FROM EACH PLURALITY THEREOF, DISPOSED IN PREDETERMINEDROTATIONAL ANGULAR POSITIONS, AND TOOL TRANSFER MEANS ALIGNED WITH SAIDPREDETERMINED POSITIONS TO EJECT TOOLS FROM SAID SELECTED OPENINGSTOWARDS SAID PRESS AND TO WITHDRAW TOOLS THEREINTO FROM SAID PRESS.